The invention relates to a method for welding a first workpiece (11) to a second workpiece (12) by means of a laser. It is an object of the invention to provide a reliable, repeatable and reproducible approach for laser welding of two workpieces one of which consists of a semiconductor material. The method proposed by the invention comprises the following steps: Irradiating the first workpiece (11) with a beam of pulsed laser radiation, wherein the first workpiece (11) consists of a semiconductor material which is transparent at the wavelength of the laser radiation, so that the beam enters the first workpiece (11) through an entrance surface and leaves it through an exit surface, the geometric focus of the beam being positioned in the plane of the exit surface; determining a delocalization of the focus caused by nonlinear interaction of the laser radiation with the semiconductor material; placing the second workpiece (12) against the first workpiece (11); and, again, irradiating the first workpiece (11) with the laser beam of pulsed laser radiation, the focus of the laser radiation being positioned along the beam direction taking into account the determined delocalization so that the intensity maximum is located in the plane of the exit surface forming the interface of the two workpieces (11, 12), whereby the first workpiece (11) is welded to the second workpiece (12). Moreover, the invention relates to a system for welding a first workpiece (11) to a second workpiece (12).

A manufacturing method of semiconductor wafers includes preparing a ingot having a first major surface and a second major surface in a back side of the first major surface, a peeling layer being formed in the ingot along the first major surface; and applying a load to the ingot from outside thereof with respect to a surface direction along the first major surface such that a moment with a supporting point which is a first end of the ingot in the surface direction acts on the ingot, thereby peeling a wafer precursor from the ingot. Also, a dynamic force may be applied to the ingot such that a tensile stress along an ingot thickness direction acts on an entire area of the ingot in the surface direction, thereby peeling the wafer precursor from the ingot.

An inspecting apparatus for inspecting an ingot having a polished surface includes a holding table configured to hold the ingot with the polished surface of the ingot exposed, a light source configured to irradiate the polished surface of the ingot held by the holding table with light at a predetermined incidence angle, an imaging unit configured to condense and photograph reflected light reflected by the polished surface of the ingot, and form a photographed image emphasizing unevenness produced on the polished surface by a crack extending in the ingot, and a control unit including a determining section configured to determine the state of the ingot by comparing the formed photographed image with a preset condition.

A laser processing apparatus includes a laser oscillator configured to emit a laser beam, a slit configured to narrow a width of the laser beam emitted from the laser oscillator to a width corresponding to a dividing groove to form the dividing groove of a predetermined width, a slit moving mechanism configured to move the slit in a direction corresponding to a width direction of the dividing groove, and an adjusting unit configured to make the center of the slit and the cross-sectional center of the laser beam entering the slit coincide with each other in a direction in which the slit moving mechanism moves the slit.

There is provided a diamond wafer dividing method used when the diamond wafer having a front surface along the {100} plane is divided at planned dividing lines along the <110> direction. The dividing method includes a first modified layer forming step of forming a first modified layer at a linear first region along the planned dividing line, inside the diamond wafer, a second modified layer forming step of forming a second modified layer at a linear second region shifted from the first region in the width direction and the thickness direction with respect to the front surface, and a dividing step of dividing the diamond wafer along the planned dividing lines by giving a force to the diamond wafer in which the first modified layer and the second modified layer are formed.

A method of processing a substrate is provided. The method includes mounting a substrate on a concave mounting surface of a mounting table and deforming a surface of the substrate into a concave shape; detecting, by a height sensor, a height of the surface of the substrate in a vertical direction; determining positions of a plurality of first focus points based on height data of the surface of the substrate, detected by the height sensor; and forming a first modification layer in the substrate by irradiating the plurality of first focus points with a laser beam.

A laser processing apparatus includes: a chuck table for holding a single-crystal SiC ingot on a holding surface thereof; a laser beam applying unit for applying a laser beam to the single-crystal SiC ingot held on the holding surface of the chuck table; and a camera unit configured to capture an image of the single-crystal SiC ingot held on the holding surface of the chuck table. The chuck table includes a porous material making up the holding surface and a glass frame made of a non-porous material and having a recess defined therein and receiving the porous material fitted therein, and a negative pressure transfer path for transferring a negative pressure to the porous material fitted in the recess.

Laser ablation processing method for debris-free and efficient removal of materials comprises the step of using a refrigeration device to condense the water vapor and form a thin frost layer on the materials at temperatures below the freezing point. The residual debris produced during the ablation process deposits on the frost layer that covers the material, which is easily removed when the frost layer melts. At the same time, the frost layer in the laser irradiation area melts to a liquid layer, which can effectively reduce the deposition of debris on the inner wall of the groove and thus improve the efficiency and quality of laser ablation. The method is applicable to debris-free laser processing on an arbitrary curved surface.

A manufacturing method of a protective film agent for laser dicing that includes a solution preparation step of preparing a solution in which at least a water-soluble resin, an organic solvent, and an ultraviolet absorber are mixed; and an ion-exchange treatment step of carrying out ion exchange of sodium ions in the solution by using a cation-exchange resin.

An optical module includes an optical semiconductor chip having a first surface that includes a laser beam irradiation region and a cleavage region, an optical fiber optically coupled to the first surface, and a support member having a second surface bonded to the first surface, and configured to support the optical fiber. The optical semiconductor chip has an optical signal input and output part located in the cleavage region, and the second surface is bonded to the first surface within the cleavage region.